This is a renewal application for the Massachusetts Institute of Technology (MIT) Center for Environmental Health Sciences (CEHS). The present mission of CEHS is the study of the biological effects of environmental agents, individually and in combination, with specific emphasis on how such exposures affect human health and the health of the ecosystem on which life depends. Looking ahead, the investigators' strategic vision is to leverage their interactive research program, along with robust community engagement efforts, to provide innovative and effective solutions to avoidable health risks caused by hazardous agents in our environment. John Essigmann (Director) and Bevin Engelward (Deputy Director) lead the CEHS, and each has demonstrated a career-long commitment to research, teaching and translation in environmental health. The CEHS research themes, which define the Center's environmental health identity, include: 1) DNA damage, DNA repair and mutagenesis, 2) the influence of microbes in susceptibility to environmentally induced diseases, 3) synergistic relationships between inflammation and environmental diseases, such as cancer and pulmonary dysfunctions, 4) the application of cutting-edge bioengineering tools to environmental health problems, and 5) chemistry and transport of air and water pollution. A signature element of the investigators' research portfolio is the integration of science, engineering and policy to solve complex problems in environmental health; the CEHS integrates the activities of 45 members across nine departments at MIT and one at Harvard. The integrative approach enables the investigators to take on the following goals: 1) to enhance the translational impact of the CEHS; 2) to enhance the involvement of engineers in the environmental health sciences; 3) to connect their outreach and engagement activities with their basic research programs; 4) to integrate into the new MIT Environmental Solutions Initiative as a central and influential stakeholder; and 5) to leverage their physical assets, intellectual assets and interactive research base to apply for multi-investigator grant support. The community engagement activities, which are in alignment with the research mission, stress two-way communication on environmental issues with their local communities, specifically with under-served communities in Boston, with the towns of the heavily industrialized Mystic River Watershed, and with Native American populations in Maine. The CEHS is supported by four Facilities Cores: 1) Genomics and Imaging, 2) Bioanalytical, 3) Animal Models, and 4) Integrative Health Sciences. A strong Pilot Project Program stimulates integration of new ideas and early-stage investigators into the CEHS, encouraging both basic and translational research. The Administrative Core coordinates all the CEHS activities via direct interactions with individual Center members, the MIT Administration, Facilities Cores and External and Internal Advisory Committees. The Administrative Core also manages the investigators' global environmental health efforts, seminar programs, career development program, poster sessions, retreats and other enrichment activities that help make the total of the CEHS greater than the sum of its parts.